Solar thermal technology, which uses heat to generate electricity, is on its comeback tour.

Like a rock band that took an extended hiatus, solar thermal technology was essentially abandoned in the 1990s after a handful of power plants were constructed in the 1980s.

But on Monday, solar thermal start-up Ausra is expected to announce that it has attracted $40 million in funding from venture capital firms Kleiner Perkins Caufield & Byers and Khosla Ventures.

The company is also expected to disclose that it has begun the permit process to build a 175-megawatt power plant in California that should be operating in about three years.

Ausra, which has sought to keep a low profile, said that its product design will make its power plants competitive with fossil fuel-based electricity in the next few years.

"We're talking about the U.S. producing its electricity and electricity for vehicles entirely within its borders. The implications for this are enormous," said David Mills, Ausra's founder and chief scientific officer who spent several years doing the basic research for the company's technology.

Ausra's plants are made up of hundreds of glass-covered metal "collectors" that concentrate sunlight on a tube filled with water. The water becomes steam which turns a conventional steam turbine.

High-pressure water storage tanks allow the company's solar thermal power plants to keep several hours' worth of electricity on tap, addressing one of the biggest hurdles of large-scale renewable energy, according to company executives.

"Energy storage is the key to enabling renewable sources of power to move from 10 to 20 percent of electricity generation to 90-plus percent," said Ausra Executive Vice President John O'Donnell.

Ausra executives said that the system can now deliver electricity at 10 cents per kilowatt hour, more than the 9 cents per kilowatt hour that natural gas power plants cost.

Once Ausra's manufacturing operations are working on a large scale, its production costs and cost of capital will go down below the price of coal-fired plants which are 6 cents per kilowatt hour, he said.

Because of regulations that require renewable sources of electricity, a number of companies are now pursuing utility-scale solar thermal power plants. Another start-up, Green Volts, recently signed a supply deal with Pacific Gas & Electric in California.

The U.S. National Renewable Energy Laboratories estimates that solar thermal technology can supply hundreds of gigawatts of electricity, or more than 10 percent of demand.

Colocated Solar is the only way to go. rooftop photovoltaics should stop

This article is right on point. If we are going to increase Solar Powers percent of our total energy production the answer is in a Co Located Solar Farm. We have high hopes for our Solar Transfer solution that also seeks to capture the most amount of suns for the lowest cost. Transferring the power is the biggest hurdle once cost to capture has been reduced. Please send Arnold Schwarzennegger and others emails to stop the million solar roofs project. It will simply never make sense to put photovoltaic capture devices on a house or office building that is connected to the grid. Tell Google and Walmart they also need to rethink their programs.

1) tell us why solar transfers are good2) define what the heck a solar transfer actually is3) define why a solar transfer has better benfits than me saving all of my usage and offsetting someone else's usage as well by selling back to the grid.4)tell me why my $20K investment isn't going to make a difference to the planet especially if it helps convince others to make the same investment and therefore my $20k invested has helped the equivalent of 10+ people offset their carbon footprint on this planet (almost as if those 10 people don't even exist to Mother Earth)please help me understand how I am going wrong here?

Putting Solar panels on ones roof might make them feel that they are sticking to the big corporations or helping the planet but residential photovoltaic installations are a waste of money and a waste at a chance to save the environment. If you have a pipe out front with energy that is cheaper and cleaner in the long run use it. Don't think that by buying $20,000 plus Solar installations for your roof you are helping the planet. You could be doing 3 to 4 times better for the environment if you went with a Solar Transfer.

Not sure why Manhattan2 is all up in arms about rooftop solar cells. I had a 2.5Kw system installed in my Southern California home, and I love watching the electric meter run backwards on sunny days. Yes, my system was relatively expensive, but it emits no pollution and will pay for itself in about 15 years. After that, it's free energy for the rest of the unit's expected 25-year life. What the @#$! is your problem, anyway?

Are you connected to the gird? For the person that has their meter run backwards does it do that 24 hours a day? If not that probably means you are connected to the grid. Your solar investment could have produced 3-4 times more power for the same dollar if you followed the logic behind a Solar Transfer. Let someone else close to your investment use your power you just get the Money. The planet comes out 3 times better! Please understand this logic. We only have one! One Earth that is!.

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